Coil component, circuit board arrangement and method of making coil component

Abstract

A coil component includes a magnetic body, made from an insulating material and metal magnetic particles joined by the insulating material. The magnetic body has a first surface and a second surface, and the first surface is adjacent to the second surface. A surface resistivity of the second surface is higher than a surface resistivity of the first surface. The coil component also includes a conductor portion provided inside or on the magnetic body. The coil component also includes an outer electrode provided on the first surface and connected to the conductor portion.

What is claimed is: 
     
         1 . A coil component comprising:
 a magnetic body, made from an insulating material and metal magnetic particles joined by the insulating material, the magnetic body having a first surface and a second surface, the first surface being adjacent to the second surface, a surface resistivity of the second surface being higher than a surface resistivity of the first surface;   a conductor portion provided inside or on the magnetic body; and   an outer electrode provided on the first surface and connected to the conductor portion.   
     
     
         2 . The coil component according to  claim 1 , wherein the magnetic body further has a third surface, which is opposite to the second surface and is adjacent to the first surface, and a surface resistivity of the third surface  1   s  higher than the surface resistivity of the first surface. 
     
     
         3 . The coil component according to  claim 2 , wherein the magnetic body further has a fourth surface, which is adjacent to the first and second surfaces, and a fifth surface, which is adjacent to the first and second surfaces and is opposite to the fourth surface, a surface resistivity of the fourth surface  1   s  higher than the surface resistivity of the first surface and a surface resistivity of the fifth surface  1   s  higher than the surface resistivity of the first surface. 
     
     
         4 . The coil component according to  claim 3 , wherein the surface resistivity of the third surface  1   s  different from the surface resistivity of the second surface 10% or less, the surface resistivity of the fourth surface  1   s  different from the surface resistivity of the second surface 10% or less, and the surface resistivity of the fifth surface  1   s  different from the surface resistivity of the second surface 10% or less. 
     
     
         5 . The coil component according to  claim 1 , wherein the magnetic body further has a sixth surface opposite to the first surface, and a surface resistivity of the sixth surface  1   s  higher than the surface resistivity of the first surface. 
     
     
         6 . The coil component according to  claim 5 , wherein the surface resistivity of any of the third to sixth surfaces is different from the surface resistivity of the second surface 10% or less. 
     
     
         7 . The coil component according to  claim 1 , wherein the outer electrode is provided within an outer periphery of the first surface when viewed in a direction perpendicular to the first surface. 
     
     
         8 . The coil component according to  claim 3 , wherein the outer electrode is spaced from the second surface, the third surface, the fourth surface and the fifth surface. 
     
     
         9 . The coil component according to  claim 1 , wherein the magnetic body is prepared by a molding process and a subsequent surface processing, and a surface resistivity of a surface of a blank, which is made by the molding process, is twice or more a surface resistivity of the blank that has undergone the surface processing.